Adamantanecarboxamidoalkanoic acids and related compounds

ABSTRACT

THE PRESENT ADAMANTANECARBOXYLIC ACID DERIVATIVES OF AMINO ACIDS POSSESS ANTI-BIOTIC ACTIVITY AGAINST A VARIETY OF ORGANISMS. THUS, THEY ARE ANTI-BACTERIAL, ANTI-PROTOZOAL, AND ANTI-ALGAL AGENTS. THE COMPOUNDS ARE PREPARED BY THE REACTION OF AN ADAMANTANECARBONYL HALIDE, PREFERABLY THE CHLORIDE, WITH AN APPROPRIATE AMINO ACID, DIPEPTIDE, OR POLYPEPTIDE.

United States Patent 3,705,141 ADAMANTANECARBOXAMIDOALKANOIC ACIDS AND RELATED COMPOUNDS Carl Peter Krimmel, Wauconda, Ill., assignor to G. D. Searle & Co., Chicago, Ill.

No Drawing. Continuation-impart of application Ser. No. 727,698, May 8, 1968, which is a continuation-in-part of abandoned application Ser. No. 467,749, June 28, 1965. This application May 17, 1971, Ser. No. 144,304

Int. Cl. C07c 103/52; C07g 7/00 US. Cl. 260112.5 4 Claims ABSTRACT OF THE DISCLOSURE The present adamantanecarboxylic acid derivatives of amino acids possess anti-biotic activity against a variety of organisms. Thus, they are anti-bacterial, anti-protozoal, and anti-algal agents. The compounds are prepared by the reaction of an adamantanecarbonyl halide, preferably the chloride, with an appropriate amino acid, dipeptide, or polypeptide.

The present application is a continuation-in-part of application Ser. No. 727,698, filed May 8, 1968, now US. Pat. 3,625,985. That application is in turn a continuationin-part of application Ser. No. 467,749, filed June 28, 1965, and now abandoned.

The present invention relates to adamantaneand homoadamantanecarboxarnidoalk-anoic acids and to amides of such acids with amino acids. Alternately, the present compounds can be considered as adamantanecarbonyl derivatives of amino acids, dipeptides, and polypeptides. Specifically, the present invention relates to compounds having the following general formula wherein Ad is selected from the group consisting of adamantyl and homoadarnantyl with, in each case, the free valence occurring at a bridgehead position; n is a small positive integer with an upper limit of 6; and --NRZ is selected from the group consisting of wherein Alk is an alkylene radical.

The alkylene radicals referred to above contain up to 10 carbon atoms and can be exemplified by methylene, ethylene, propylene, trimethylene, tetramethylene, pentarnethylene, decamethylene, and the like.

The compounds of this invention are useful because of their anti-biotic activity. In particular, they inhibit the growth of bacteria such as Diplococcus pneumoniae, protozoa such as Tetrahymena gelleii and Trichomonas foetus, and algae such as Chlorella vulgaris. The present compounds can thus be combined with various known excipients and adjuvants in the form of dusts, solutions, suspensions, ointments, and sprays to provide compositions useful for disinfecting purposes. These compounds also inhibit germination of seeds of trifolium.

The compounds of the present invention are conveniently prepared by the reaction of an adamantane-lcarbonyl halide or a homoadamantane-3-carbonyl halide, preferably the chloride, with an appropriate amino acid, dipeptide, or polypeptide. The reaction is carried out in an aqueous solution in the presence of a base such as sodium hydroxide. The compounds in which n in the above formula is greater than 1 can alternately be prepared by the reaction of an acid chloride of the formula 0 Adi. l(N RZ-](]J-) nCl wherein the various groups are defined as above, with an appropriate amino acid, dipeptide, or polypeptide.

The following examples are presented to further illustrate the present invention; they should not be construed as limiting it in spirit or in scope. In these examples, quantities by weight are indicated in grams, quantities by volume are indicated in milliliters, and temperatures are indicated in degrees centigrade C.).

EXAMPLE 1 A mixture of 3.0 grams of adamantane-l-carboxylic acid and 20 m1. of thionyl chloride is refluxed on a steam bath for 30 minutes. The mixture is then distilled under reduced pressure to remove excess thionyl chloride. Azeotropically dried benzene is added to the residue and vacuum distillation is resumed to remove the final traces of thionyl chloride. The residual adamantane-l-carbonyl chloride is then dissolved in 100 ml. of dry acetone and the resultant solution is added, in one batch, to a vigorously stirred solution of 1.9 grams of glycine and 2.8 grams of sodium hydroxide in ml. of water. The resultant warm reaction mixture is then heated on a steam bath to remove the acetone. The aqueous solution is then treated with decolorizing charcoal, cooled, and acidified with dilute hydrochloric acid. The solid precipitate which forms is separated by filtration and washed twice with SO-ml. portions of cold water and dried. The solid is then recrystallized from ml. of refluxing Z-butanone to give white crystals of N-(adamantane-l-carbonyl) glycine melting at about 191-195 C. This compound, at a concentration of 1,000 mcgm./ml., inhibits the multiplication of the organism T richomonas foetus. It has the following formula EXAMPLE 2 Homoadamantane-3-carbonyl chloride is prepared from 2.9 grams of homoadamantane-3-carboxylic acid according to the procedure for the preparation of adamantanel-carbonyl chloride described in Example 1. The acid chloride is dissolved in ml. of dry acetone and added in one batch, with stirring at room temperature, to a solution of 1.9 grams of glycine and 2.8 grams of sodium hydroxide in 70 ml. of water. The acetone is removed by heating the mixture on a steam bath and the hot aqueous residue is treated with decolorizing charcoal and filtered. The resultant filtrate is cooled, filtered through diatomaceous earth, cooled in ice, and made acidic with dilute hydrochloric acid. A tacky white precipitate forms and, on standing, becomes a powder. This is separated by filtration, washed with 2 portions of ice water, dried in a steam cabinet, and recrystallized from Z-butanone. The product obtained is analytically pure N-(homoadamantane-3-carbonyl) glycine melting at about 162184 C.

EXAMPLE 3 The procedure of Example 1 is repeated using 2.2 grams of fi-alanine in place of the 1.9 grams of glycine. The crude product is recrystallized from 100 ml. of refluxing Z-butanone to give white flaky crystals of N-(adamantane-l-carbonyl)-fl-alanine melting at about 178-183 C.

3 EXAMPLE 4 2.6 grams of 'y-aminobutyric acid is substituted for the 1.9 grams of glycine and the procedure of Example 1 is repeated. The crude product is dissolved in 120 ml. of refluxing acetone and the resultant solution is treated with decolorizing charcoal and then cooled in an ice bath. The solid which precipitates is separated by filtration and then dried to give white crystals of N-(adamantane-l-carbonyl)-'y-aminobutyric acid melting at about 158-162 C. This compound, at a concentration of 1,000 mcgm./ml., inhibits the multiplication of the organism Trichomonas foetus.

EXAMPLE 5 The acid chloride from 4.0 grams of adamantane-lcarboxylic acid is reacted with a solution of 2.9 grams of w-aminocaproic acid and 3.8 grams of sodium hydroxide in 95 ml. of water according to the procedure described in Example 1. The crude final product is obtained as a tacky white gum which solidifies on standing. This solid is washed with water and then air dried before it is dissolved in 30 ml. of Z-butanone. The resultant hot solution is filtered through decolorizing charcoal and infusorial earth. The solution is then concentrated, seeded, and cooled. The solid which forms is separated to give N-(adamantane-l-carbonyl)-w-aminocaproic acid melting at about 104-120 C. This compound has the following formula EXAMPLE 6 A solution of 8.0 parts of adamantane-l-carbonyl chloride in 200 ml. of dry acetone is added in one batch, with vigorous stirring at room temperature, to a solution of 10.1 grams of ll-aminoundecanoic acid, 7.6 grams of sodium hydroxide, and 200 ml. of distilled water. The mixture is heated on a steam bath to remove the acetone and the aqueous residue is cooled in ice and acidified with dilute hydrochloric acid. The precipitate which forms is separated by filtration, dried in a steam cabinet, and recrystallized from Z-butanone to give N-(adamantane-l-carbonyl)-1l-aminoundecanoic acid melting at about 122- 127" C. This compound has the following formula EXAMPLE 7 The acid chloride from 4.0 grams of adamantane-lcarboxylic acid is reacted with a solution of 4.4 grams of N-glycylglycine and 5.3 grams of sodium hydroxide n 130 ml. of water according to the procedure described in Example 1. The aqueous solution obtained after evaporation of the acetone is acidified with dilute hydrochlorlc acid. The precipitate which forms is separated by filtration and the filtrate is concentrated under reduced pressure at room temperature. The crystalline product which forms in the concentrated filtrate is separated byfiltration. It is N- [N-(adamantane-l-carbonyl)glycyl]glycine and it melts at about 16ll69 C. This compound, at a concentration of 1,000 mcgm./ml., inhibits the multiplication of the organism T richomonas foetus. It has the following formula EXAMPLE 8 Adamantane-l-carbonyl chloride is prepared from 3.6 grams of adamantane-l-carboxylic acid according to the procedure described in Example 1. The acid chloride is dissolved in ml. of dry acetone and it is added in one batch, with vigorous stirring at room temperature, to a solution of 5.0 grams of N-(N-glycylglycyl) glycine and 8.4 grams of sodium bicarbonate in ml. of distilled water. After the initial foaming subsides, the reaction mixture is heated on a steam bath to evaporate the acetone. The aqueous residue is then cooled, filtered through diatomaceous earth and acidified with dilute hydrochloric acid. The precipitate which forms is separated by filtration, washed with water, and dried, and the dried product is refluxed with 300 ml. of 2-tbutanone. Partial solution takes place and the resulting hot suspension is filtered. The filtrate is concentrated to half the original volume and cooled to room temperature. It is then filtered again and, on further standing, a microcrystalline precipitate forms. This is separated by filtration to give N-{N- [N(adamantane l-carbonyl)glycycl]glycyl} glycine. This compound has a melting point of about 184l93 C. and it has the following formula EXAMPLE 9 7.3 grams of adamantane-l-carboxylic acid is converted to adamantane-l-carbonyl chloride by the procedure described in Example 1. The acid chloride is dissolved in 250 ml. of dry acetone and this solution is added, with stirring, to a solution of 6.9 grams of L-proline and 15.1 grams of sodium bicarbonate in ml. of water. When the initial foaming subsides, the reaction mixture is heated on a steam bath to evaporate the acetone. The hot solution is then treated with charcoal, filtered through diatomaceous earth, cooled to room temperature and then in an ice bath, and acidified with dilute hydrochloric acid. The precipitate which forms is separated by filtration and washed with water until the washings are free of acid. The solid material is then dried in a steam cabinet, dissolved in hot benzene, and filtered hot. The resultant solution is cooled and the precipitate which forms is separated by filtration to give N adamatane l-carbonyl-L-proline melting at about 190 C.; [a] -=125 in cholorform c.=1.001%). This compound has the following formula EXAMPLE 10 The acid chloride from 4.3 grams of homoadamantane- 3-carboxylic acid is dissolved in dry acetone and reacted with a solution of 4.4 grams of N-glycylglycine and 5.3 grams of sodium hydroxide in 130 ml. of water according to the procedure described in Example 7. The product obtained in this way is N-[N-homoadamantane-S-carbonyl)- glycyl] glycine.

EXAMPLE 11 8.0 grams of adamantane-l-carbonyl chloride is reacted with 20 grams of ll-(1l-aminoundecanamido)undecanoic acid according to the procedure described in Example 6. The product obtained is ll-[ll-(adamantanel-carboxamido -undecanamido] undecanoic acid.

, 5 6 What is claimed is: 3. A compound according to claim 1 which is N-[N- 1. A compound of the formula (adamantane-l-carbonyl)glycyl] glycine.

4. A compound according to claim 1 which is N-{N- wherein Ad is selected from the group consisting of ada- 5 References Cited mantyl and homoadamantyl; n is 2 or 3; Alk is alkylene containing up to 10 carbon atoms. UNITED STATES PATENTS 2. A compound according to claim 1 which has the 3,345,399 10/ 1967 Gerzon et al. 260-468 formula 10 3,369,041 2/1968 Gerzon et a1 260482 3,625,985 12/1971 Krimmel M 260112.5

ELBERT L. ROBERTS, Primary Examiner U.S. Cl. X.R.

wherein n is 2 or 3. 

